Variation and Reproduction:

How do we get characteristics from our parents? What is the unit of inheritance?

genes are passed on in the sex cells (gametes) which we are developed from, from our parents. Unit of inheritance is genes.

Where in the cell is the genetic information?

The nucleus

Describe the structure of a chromosome:

Chromosome is made up of DNA (Deoxyribonucleic acid), which is in the form of a string molecule, in a double helix shape. Genes are sections of DNA, and chromosomes are collections of genes and come in pairs.

What does DNA stand for, and what does it look like?

Deoxyribonucleic acid, looks like a twisted ladder (double helix)

How many chromosomes does a human have?

46 chromosomes, 23 pairs.

What are alleles?

Pairs of genes that code for the same characteristic on a pair of chromosomes, can be dominant or recessive.

What is asexual reproduction? What kind of organisms reproduce this way, and what are the offspring called?

Only involves one parent, no joining of sex cells, no variety of offspring. Common in small animals, plants and bacteria. body cells reproduce asexually. Offspring are clones.

What is Sexual reproduction? What types of organisms reproduce this way and what are their offspring like?

Where sex cells meet (gametes) and join to create an individual. Many organisms, bacteria to people, offspring have variety.

What is an advantage and a disadvantage of Sexual reproduction?

Advantage: Variety is introduces, Disadvantage:Risky because it relies on sex cells meeting.

What sort of characteristics do genes control?

Eye colour, hair colour, whether you have dimples etc.

What factors make you different from other people?

The genetic information you got from your parents (nature) or the environment you grew up in (nurture).

How can you investigate variety?

grow plants in different conditions, study genetically similar animals, look at twins and siblings.

What is a clone?

an organism that is genetically identical to another organism.

How are plants cloned by taking cuttings?

remove a small piece of plant and use plant hormone to stimulate root growth. Quick and cheap.

How are plants cloned by tissue culture?

mix plant hormones with a small group of cells, then separate them to grow thousands of plants. More expensive than cuttings.

How does embryo cloning work?

Early embryo is removed before cells are specialized. and the cells are separated out to make new embryos, and then implanted in mother cows. babies are clones of each other.

What are the benefits and drawbacks of embryo cloning?

Benefits: Can transport embryos across the world, more calves from a prize cow, can make copies of GM embryos. Drawbacks: Cannot predict personality, cannot see the adult version of the offspring, unknown entity.

Describe the process of Adult cell cloning:

Nucleus is removed from an adult body call and put into an empty ovum, tiny electric shock is given to join them, and it starts to divide to from an embryo, which is implanted into the mother.

Human insulin gene cut out with an enzyme, plasmid removed from bacteria and split open. gene inserted into plasmid using another enzyme, plasmid inserted into bacteria, bacteria reproduce, insulin is made when gene is switched on.

What are the benefits and disadvantages of genetic engineering?

Benefits: make large amounts of proteins with bacteria, improve growth rate in plants and animals, larger yields, grow well in different environments, anti pest/frost.